This disclosure relates generally to satellite navigation signal receivers, such as Global Navigation Satellite System (GNSS) receivers, and more particularly, to methods and apparatuses for efficiently combining satellite navigation signals.
The conventional Global Positioning System (GPS) traditionally transmitted only one signal (e.g., GPS L1 C/A code) to consumer users. Modern satellite systems, like in the Galileo positioning system, however, may transmit more than one signal on the same frequency for various purposes (including, for instance, providing secure signals not intended for use by most users, and providing multiple signals split between data and pilot channels). In the case of the Galileo system, two signals (Galileo E1-B and E1-C signals) are provided on the same frequency with 50% of the power being transmitted in each of the signals.
Conventional systems may combine signals from a single satellite to boost signal strength and optimize receiver acquisition, tracking sensitivity, and operation under dynamics. However, conventional systems lack the ability to combine signals in a way that permits the combined signal to be processed efficiently, for instance as a single-bit signal using a single channel per satellite.